The movie version of the book has been getting some mediocre reviews. Some reviewers say that it was pieced together weirdly, it tried too hard, it didn't have a definitive plot, etc. And I beg to disagree with those negative reviewers. I went to see the movie with a big group of my friends and we all basically fell in love with it. I think you have to be a teen to enjoy and get the meaning of it. The actors in the movie embody the whole spontaneous shifty chaotic lives of real teens so the movie was really convincing to me.
I had my doubts with the cast of the lead roles at the beginning of the movie's production, but seeing it all melded together proved to me that Michael Cera and Kat Dennings have some sort of strange chemistry. They actually, to my huge surprise, made me believe they were the Nick and Norah of the book.
And, also to my surprise, I found that I appreciated the book more after seeing the movie. I kind of have a new found respect for it and will probably go back and reread it eventually so I can absorb it again. It's the kind of book that can be taken in a lot of different ways, and I just think I understood it wrong the first time through.
I'd definitely recommend going to see Nick and Norah's Infinite Playlist in theaters. It's funny, convincing, and real. A good movie.